MoS2-based Nanocomposite Electrode for High Performance Supercapacitors

  • 蘇 費翠

Student thesis: Doctoral Thesis

Abstract

MoS2 as two dimensional with unique properties has attracted many researchers for many applications such as solar cell Li-ion battery Na-ion battery and electro catalysis for HER In this research work MoS2 and related Mo-based materials have been demonstrated for electrode material of supercapacitor Nanostructuring and coupling with other materials such as vapor grown carbon nanofibers (VGCNFs) activated carbon clothes (ACC) and polypyrrole Direct growth of MoS2 nanowalls on VGCNFs has been achieved using a microwave-assisted hydrothermal (MAH) method under an acidic condition The acidic condition was obtained through the addition of an HCl aqueous solution We demonstrate that the HCl not only modifies the pH value for limiting the growth rate but also leads to the formation of NaCl which is the key for the direct and unique growth of MoS2 on the VGCNF surface A growth mechanism is therefore proposed The growth of MoS2 onto the high electrically conducting VGCNF creates a unique structure that not only reduces the aggregation of MoS2 but also improves the electrical conductivity of the resulting composite electrode hence enhanced the electrochemical performance Likewise the growth of MoS2/MoOx on ACC was also prepared through (MAH) It was found that MoOx sub oxides are MoO3 and MoO2 The growth of MoS2/MoOx on activated VGCNF and ACCs create a unique structure that favors ions intercalation The conductive ACCs MoO3-x and monoclinic MoO2 provide fast electron transport while the MoS2 nanosheets/MoO3-x nanoparticles nanostructure improves the capacitance These materials are shown to be promising candidate electrode materials for supercapacitor Moreover an asymmetric supercapacitor (ASC) was built with MoO3/PPy/MoS2 and PPy nanotube/N-doped graphene (NDG) as positive electrode and negative electrode respectively PPy nanotube/NDG was easily synthesized through MoO3 template-assisted polymerization followed by microwave-assisted hydrothermal Nanotube formation and doping of reduced graphene oxide simultaneously occurred due to the presence of nitrogen precursor Moreover novel ternary nanocomposite MoO3/PPy/MoS2 was fabricated through facile method This combination provides a novel material system for high performance of ASC
Date of Award2018 Jul 26
Original languageEnglish
SupervisorJyh-Ming Ting (Supervisor)

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